package string;

public class StringBuilderDemo {
    public static void main(String[] args) {

        String str="好好学习java";
        StringBuilder builder=new StringBuilder(str);
        builder.append(",为了找个好工作");
        System.out.println(builder);

        builder.replace(9,16,"就是为了改变世界");
        System.out.println(builder);



        builder.delete(0,9);
        System.out.println(builder);
        builder.insert(0,"活着");
        System.out.println(builder);





















        /*
        StringBuilder  builder1=new StringBuilder();  //空字符串
        StringBuilder  builder2=new StringBuilder("abc"); //abc串


        String str="abc";
        StringBuilder builder3=new StringBuilder(str);  //abc串
        String str2=builder3.toString();




         */








    }
}
